Gas streams often carry particulate material therein. In many instances, it is desirable to remove some or all of the particulate material from a gas flow stream. For example, air intake streams to engines for motorized vehicles or power generation equipment, gas streams directed to gas turbines, and air streams to various combustion furnaces, often include particulate material therein. The particulate material, should it reach the internal workings of the various mechanisms involved, can cause substantial damage thereto. It is therefore preferred, for such systems, to remove the particulate material from the gas flow upstream of the engine, turbine, furnace or other equipment involved.
In other instances, production gases or off gases from industrial processes may contain particulate material therein, for example, those generated by the process. Before such gases can be, or should be, directed through various downstream equipment and/or to the atmosphere, it may be desirable to obtain substantial removal of particulate material from those streams.
A variety of air filter or gas filter arrangements have been developed for particulate removal. In general, however, continued improvements are sought.